Nanophotonic visible light phased arrays

Abstract

Previously demonstrated integrated optical phased arrays have primarily been implemented in silicon-based platforms and have therefore been limited to operation at infrared wavelengths, where silicon provides low-loss transmission. Developing integrated optical phased arrays for visible wavelengths would enable the exploration of new applications for this technology, such as autostereoscopic displays and neuronal targeting for optogenetics. The work presented in this thesis involves the development of visible light integrated optical phased array components and systems with a focus on autostereoscopic image projection applications. Practical 3D microdisplay applications will require (1) large-aperture phased array systems for diffraction minimization, (2) integrated phase modulation for implementing dynamically reconfigurable phased array antenna elements, and (3) a phased array system architecture for accurately encoding the light field of virtual objects. Integrated photonic architectures for all three aforementioned goals are investigated in this thesis. With respect to the first goal, a 1x1 mm2 aperture visible light phased array with a near diffraction limited far-field spot size is demonstrated. With respect to the second goal, the design of an integrated phase modulator based on the electro-optic tuning of a nematic liquid crystal waveguide cladding layer is developed and a near-x phase shift is demonstrated in a fabricated device. Finally, an autostereoscopic image projection system comprised of multiple tiled phased arrays configured to project a virtual image with parallax in one dimension within an 8.58° field of view is demonstrated.